Fluorescein Peptide Modifications - Dyes and Quenchers
UV-excitable dye, used in enzyme assays using cuvettes or flow cytometry.
Cy3, Cy5 are dyes with extremely high extinction coefficients and fluorescence. Thus, they are especially suitable for very sensitive localization assays of peptides in cells.
Their disadvantage is the high instability of the molecules under peptide synthesis
Therefore the yields are comparatively low.
Dabcyl is a non-fluorescent dye predominantly used as a quencher for other fluorophores (esp.
Fluorescein type dyes, EDANS.).
If Dabcyl is coupled to a peptide in close proximity to a fluorophore, it absorbs the emitted light of the
fluorophore. Enlarging this distance (i.e. by enzymatic cleavage of the peptide) results in excitation of
the fluorophore with an emission signal that can be detected.
Dansyl is also used as a fluorophore quencher. Unlike Dabcyl, it inherits own fluorescence and thus
might not be as useful for highly sensitive assays.
2,4-Dinitropheny is a non-fluorescent dye that can be used as a fluorophore quencher (see Dabcyl for more details).
DNP-Lysineis a non-fluorescent dye that can be used as a fluorophore quencher, for custom peptide
(see Dabcyl for more details).
EDANS (5-((2-aminoethyl)amino)napthalene-1-sulfonic acid)
EDANS is a commonly used dye in FRET (fluorescence resonance energy transfer) peptides in combination with Dabcyl as quencher.
Fluorescein is the commonly used fluorescent dye in confocal laser-scanning microscopy and flow cytometry applications.
NBD (7-nitrobenz-2-oxa-1, 3-diazole)
NBD is a fluorescent dye, used for amine modification.
p-Nitro-Aniline is a chromogen used as colorimetric enzyme substrate in many standard enzyme assays in cuvettes.
Rhodamine B represents one among a numerous range of rhodamine dyes, used in fluorescent peptide
Tamra is the most commonly used rhodamine dye in fluorescence assays.